Wall insulation system providing improved moisture control

ABSTRACT

Disclosed are an insulation product and an insulation system incorporating such a product for insulating exterior walls, particularly masonry walls, that incorporates a wicking media to transport condensate away from the interface between the insulating product and the exterior wall. The condensate will be removed to a more interior location where it can evaporate and/or be transferred to and held in a sorbent material until conditions allow permit evaporation. The insulation system includes an integrated support element that can be used to increase the rate of evaporation via various methods and/or improve the aesthetic appearance of the insulating product. The evaporation rate may be improved through the use of increased wicking material area, secondary evaporative surfaces, heating and/or forced or natural convection.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY

This invention relates generally to a method and apparatus forinsulating masonry walls that provides improved moisture control at theinterface between the insulation material and the masonry wall. Moreparticularly, this invention pertains to an insulating process andapparatus in which one or more vapor barrier, sorbent and wickingmaterials are used in an insulation product that is applied to a masonrywall to reduce or prevent the formation of liquid water on the masonrywall.

BACKGROUND OF THE INVENTION

The exterior walls of a building are typically insulated in order toreduce the heating and cooling demands resulting from variations betweenthe exterior temperature from the desired interior temperature. A widerange of fibrous, solid and foam insulating materials have been used toachieve this insulation, with a common insulating material being facedor unfaced batts of mineral or glass fibers.

When using a faced insulating product in which a facing layer, such asasphalt-coated Kraft paper or a polymeric film, is adhered to theinsulating layer, the insulation product is typically installed with thefacing layer positioned toward the interior space. This orientationtends to reduce infiltration or diffusion of the moisture-laden interiorair through the insulating layer to the interface between the insulatingproduct and the exterior wall. Particularly in climates with longheating seasons and/or extremely cold temperatures, using facedinsulation products limits the amount of moisture from the interior airthat can reach the cooler exterior wall and condense to form liquidwater on the surface of the exterior wall.

As used herein, masonry walls include constructions utilizing claybrick, concrete brick or block, calcium silicate brick, stone,reinforced concrete and combinations thereof. Water present at theinterface between the insulating product and the inside surface of theexterior wall and/or the outer portion of the insulation product isassociated with a host of problems including mold growth, efflorescence,reduced insulating efficiency and, if sufficiently cold, frost spallingresulting from water freezing and expanding within cracks and gaps inthe masonry.

A major contributing factor to the accumulation of water at theinterface and the resulting decreased performance of the associatedmasonry wall system is the leakage of warm humid air through thebuilding envelope to surfaces that are at temperatures below the dewpoint of the adjacent air and the associated accumulation ofcondensation within the insulating layer and/or on the inside surface ofthe exterior wall.

A need thus exists for an improved method of insulating exterior walls,particularly masonry walls, that provides improved control of water,particularly that resulting from the condensation of water vapor, at theinterface between an inside surface of the exterior wall and the outersurface of the insulation product applied to the wall.

SUMMARY OF THE INVENTION

To solve the problems outlined above, the present invention provides aninsulation product and an insulation system incorporating such a productfor insulating exterior walls, particularly masonry walls, thatincorporates a wicking media to transport condensed water from theinterface between the insulating product and the exterior wall to a moreinterior location where it can evaporate and/or a sorbent material forholding water. An active layer or layers comprising one or more of awicking fabric, wicking media and sorbent material is provided on ornear the exterior surface of the primarily insulating layer. When theinsulating product is installed, the active layer will be closelyadjacent and/or in contact with an inside surface of the exterior wall.

The insulation product is preferably installed with a correspondingsupport element to form an insulation system. The support element willtypically be provided along the lower edge of the insulation product anddefine a space between the insulation product and the floor. The supportelement may comprise several cooperating elements or structures and may,for example, include a baseboard portion to create a more finishedappearance for the interior surface of the insulation system.

This space defined by the insulation system may be used for routing anextension portion of the primary wicking material toward and/or into theinterior space in order to increase the evaporation rate. Additionalelements, such as vents, grills, fans, ducts, sorbent material,secondary wicking materials and heaters, may be included in or connectedto the support element for further improving the performance of theinsulation system.

Various objects and advantages of this invention will become apparent tothose skilled in the art from the following detailed description of thepreferred embodiment, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIGS. 1-4 are cross-sectional views of exemplary embodiments of aninsulation product and insulation system according to the invention; and

FIGS. 5-11 are cross-sectional views of portions of exemplaryembodiments of an insulation system according to the invention.

These drawings have been provided to assist in the understanding of theexemplary embodiments of the invention as described in more detail belowand should not be construed as unduly limiting the invention. Inparticular, the relative spacing, positioning, sizing and dimensions ofthe various elements illustrated in the drawings are not drawn to scaleand may have been exaggerated, reduced or otherwise modified for thepurpose of improved clarity. Those of ordinary skill in the art willalso appreciate that a range of alternative configurations have beenomitted simply to improve the clarity and reduce the number of drawings.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

As shown in FIG. 1, the insulation system 100 will be installed adjacentan inside surface of an exterior wall 10 and above a floor 12. Theinsulation system will include a primary insulating layer 14, typicallya mineral or glass fiber web and a wicking material layer 16, providedon the outside surface of the insulating layer. As installed, thewicking material layer 16 will be adjacent to and will preferably haveat least portions in contact with the inside surface of the exteriorwall 10. The wicking material layer 16 may be attached to the primaryinsulating layer 14 using any suitable method such as melt bonding ordiscontinuous adhesive layers.

Thus positioned, the wicking material layer 16 will preferentiallycollect water as it is formed by the condensation of water vapor 18 thathas diffused through the primary insulating layer 14 from the interiorspace 24, typically a heated room, to a point near or at the cool,inside surface of the exterior wall 10 where the temperature falls belowthe dew point of the moisture content of the air. Similarly, the wickingmaterial layer 16 will collect water 20 that diffuses or seeps throughthe masonry wall 10 from its outside surface, particularly forsubsurface portions of the exterior wall that are not completely sealed.In addition to seepage, it will be appreciated that in those regionssubject to periods of hot, humid weather, water vapor diffusing from theenvironment outside the exterior wall may condense as it reaches thecooler inside surface resulting from the air conditioning of theinterior space 24.

The wicking material layer 16 is preferably a non-woven material thatcan be formed from a polymer or natural fiber. One suitable polymer formanufacturing the wicking material is rayon. Rayon fibers may bestriated, or include channels, along the length of the fiber, whichprovide capillary channels within the individual fibers so the wickingaction does not depend solely upon capillary action resulting from thechannels formed between two adjacent fibers.

In addition to rayon fibers, other polymeric fibers including polyester,nylon, polypropylene (PP) and polyethylene terephthalate (PET), may bemanufactured or processed in a manner that will produce fibers includingstriations or channels on their surface. A number of fiberconfigurations have been developed that provide a plurality of surfacechannels for capillary transport of water and have been widelyincorporated in active wear for improved comfort. These types ofmaterials can be collectively referred to as capillary surface materials(CSM) and include so-called deep-grooved fibers that have high surfacearea per unit volume as a result of their complex cross-sectionalconfiguration. The capillary material layer can be provided in differentconfigurations including, for example, a non-woven film or a fine meshconfiguration.

As a result of gravity, the wicking material layer 16 will tend totransport any water 21 that condenses at the interface between theinsulation product 100 and the exterior wall 10 downwardly along theinterface and, near the lower edge of the insulation product, inwardlytoward the interior space 24. The portion of the wicking material layer16 extending toward or into the interior space 24 will allow the waterto evaporate as water vapor 26 into the interior space without drippingand without accumulating on the inside surface of the exterior wall 10.

There are several methods to form the wicking material which may beconfigured as a non-woven film and/or as a relatively fine mesh. Thefibers can be laid down dry with an acrylic emulsion being applied tothe fibers and then cured by heating or UV radiation exposure. Standardfiber binding emulsions such as acrylic or EVA (ethylene vinyl acetate)can be utilized.

As illustrated in FIG. 2, in another embodiment of the invention thebasic insulating material of FIG. 1 may be modified to include a vaporretarding layer 30. The presence of the vapor retarding layer 30 willtend to reduce the amount of moisture 18 from the moisture ladeninterior air diffusing through the primary insulating layer 14 byblocking a portion 18 a of the vapor. By limiting the amount of moisturethat can reach the cool inside surface of the exterior wall and/oradjacent materials, the vapor retarding layer can reduce the amount ofcondensation 21 that will be formed and removed through the wickingmaterial layer 16.

As illustrated in FIG. 3, in another embodiment of the invention thebasic insulating material of FIG. 1 may be modified to include a layerof sorbent material 28. The sorbent material layer 28 will tend toabsorb water in excess of the volume that can be successfullytransported through the wicking material layer 16 and reduce thelikelihood of water being present at the inside surface of the exteriorwall 10 even during periods of excessive condensation or seepage. Thesorbent material layer 28 will cooperate with the wicking material layer16 to provide a “damping” effect whereby periodic increases in thevolume of water can be removed over a longer period of time and reducethe volume of the wicking layer required to remove the condensate fromthe interface region. The sorbent material layer 28 may be a separatepremanufactured layer that is laminated to the primary insulating layer14 along with the wicking material layer or may be applied to theprimary insulating material as a liquid and then dried, cured and/oractivated to form a sorbent surface region within the primary insulatinglayer.

As illustrated in FIG. 4, depending on the volume of condensate andseepage that are anticipated for a particular installation, the wickingmaterial layer 16 present in the insulation product illustrated in FIG.1 may be replaced by a layer of sorbent material 28. Such an embodimentmay be of particular utility for installations in which brief periods ofhigh humidity are separated by longer periods of relatively lowhumidity. In such an environment, the sorbent material layer 28 willcollect and hold the condensate formed from diffusing moisture 18 duringperiods of high humidity and allow the water vapor 23 to evaporate anddiffuse back through the primary insulating layer 14 during periods oflow humidity, thereby reducing or preventing the formation of water onthe inside surface of the exterior wall 10. A variety of sorbentmaterials may be used to form the sorbent material layer 28, but willgenerally be characterized by their ability to absorb and hold at leastabout five times, and preferably at least about ten times, their weightin water.

As illustrated in FIG. 5, the basic insulating product of FIG. 1 may beincorporated with a support element to form an integrated insulatingsystem. The support element may comprise one or more separatecooperating elements including a primary support element 32, a fascia ortrim element 32 a and one or more connecting or holding elements 32 b inorder to simplify assembly, but will typically define a space into whichan extending portion 16 a of the wicking material layer 16 will extendtoward the interior space 24. The primary support element 32 and/or thetrim element 32 a may include openings such as vent holes 34 or a grill(not shown) to provide for evaporation of the water in the lower portionof the wicking material layer 16 into the interior space 24.

As illustrated in FIG. 6, the support element may incorporate a sorbentmaterial 36 that is positioned in contact with the extending portion ofthe wicking material layer 16 a to provide extra water capacity in thecase of periodic increases in the volume of water being removed from theinterface between the insulating product and the exterior wall.

As illustrated in FIG. 7, the support element may also incorporate otherelements such as a heating element 38 to assist in the evaporation ofwater from the extending portion 16 a of the wicking material layer. Asillustrated in FIG. 8, the support element may configured to provideadditional space for holding a second wicking and/or absorbent materialelement 40 for increasing the evaporative area and thereby increase thevolume of water that can be removed from the interface between theinsulating product and the interior surface of the exterior wall. Thesupport element may also define one or more passages 42 through whichair or another gas may be forced by a fan or blower to increase the rateof evaporation from the surfaces of the second wicking element 40 and/orthe extending portion 16 a of the wicking material layer 16.

As illustrated in FIGS. 8 and 9, the primary support element 32 may bemounted on the inside surface of the exterior wall at a position abovethe floor, FIG. 8, or on or closely adjacent the floor, FIG. 9. Theconfiguration illustrated in FIG. 9 also allows direct attachment to thefloor (not shown) and/or the inside surface of the exterior wall 10. Ineither configuration, the trim or fascia portion 32 a will typically beconfigured so that it can be attached, either permanently or removably,to the primary support element 32, typically in a manner that will alsoengage at least the extending portion 16 a of the wicking material. Thetrim element, whether incorporated in a unitary support element or, moretypically, provided as a separate complementary element 32 a that issubsequently attached to the primary support element 32, will tend to beconfigured with a region that extends over a lower portion of thesurface of the insulating product to provide a more finished andaesthetically pleasing appearance.

As illustrated in FIG. 10, the support element may include a primarysupport element 32 that is fastened in some fashion to the insidesurface of the wall 10 and/or the floor 12 (not shown). The primarysupport element may be configured to provide for some range of verticaladjustment during installation so as to provide a substantially levelsupport surface onto which the lower surface of the insulating elementmay be placed during installation. As illustrated in FIG. 10, theinsulating element may include both a primary insulating layer 14 and awicking material layer 16. The wicking material layer will typicallyinclude an extending portion 16 a that will tend to drape over a forwardportion of the primary support element 32, or at least cover a portionof the top surface of the primary support element 32, as the insulatingelement is set into place.

The insulating system may then be completed by attaching a trim element32 a to the primary support element 32. The trim element 32 a mayinclude one or more projections 32 b or recesses (not shown) which willcooperate with complementary structures provided on the primary supportelement 32 for securing the trim element to the primary support elementof the supporting element. As illustrated in FIG. 10, the projection 32b or other fastening structures provided on the trim element 32 a andprimary support element 32 may also be configured to engage and hold theextending portion 16 a of the wicking material layer within thesupporting element. As further illustrated in FIG. 10, the primarysupport element 32 and or the trim element 32 a may be configured todefine one or more raceways 44 in which cables, typically communicationand networking cables 36 can be concealed and secured within thesupporting element.

As illustrated in FIG. 11, the primary support element 32 or the trimelement 32 a (not shown) may be provided with one or more elements orstructures as illustrated in FIGS. 5-8 for increasing the rate ofevaporation of the water and/or condensate reaching the extendingportion 16 a of the wicking material layer 16. In the particularembodiment illustrated in FIG. 11, the primary support element isprovided with a secondary evaporative and/or wicking material 40 isconfigured with regions or structures 40 a that will increase theeffective surface area 40 a or permeability (not shown). The secondarymaterial 40 includes a contact region at which direct contact may beestablished between the primary portion (not shown) or, more typically,a region of the extending portion 16 a of the wicking material layerwhen the insulating system is assembled. As a result of this contact, aportion of the water and/or condensate reaching the extending portion 16a of the wicking material layer will transfer to the secondaryevaporative and/or wicking material 40 where it may be more readilyevaporated as a result of the increased surface area provided by the finstructures 40 a. As will be appreciated, the secondary evaporativeand/or wicking material 40 may assume a wide range of configurationswithin, and/or partially without, the support element housing. It willalso be appreciated that the particular embodiments illustrated anddiscussed herein, while exemplary, are not to be considered limiting orexhaustive and that a wide variety of configurations may be utilized toachieve the desired functionality and/or adapt the insulating system formore and less challenging conditions.

As also shown in FIG. 11, the trim element 32 a may incorporate otherstructures such as a raceway 44 for communication or power cables 46.The raceway may be configured to maintain a separation between thecables and the moisture remediation elements of the wall insulatingsystem. The raceway may also be configured in a manner that will allowit to be opened to the interior space 24 for insertion and removal ofcables 44 without requiring detaching of the trim element 32 a from theprimary support element (not shown).

The principle and mode of operation of this invention have beendescribed in its preferred embodiments. However, it should be noted thatthis invention may be practiced otherwise than as specificallyillustrated and described without departing from its scope.

1. An insulation product for exterior walls comprising: a primaryinsulating layer having an inner surface, an outer surface and lowersurface; and a wicking material layer having a primary portion providedon the outer surface of the primary insulating layer for collection andtransport of a liquid and an extending portion positioned below thelower surface for evaporation of the liquid.
 2. An insulation productfor exterior walls according to claim 1, further comprising: a vaporretarding layer provided on the inner surface of the primary insulatinglayer.
 3. An insulation product for exterior walls according to claim 1,wherein: the wicking material layer covers substantially the entireouter surface of the primary insulating layer.
 4. An insulation productfor exterior walls according to claim 1, further comprising: a sorbentregion provided adjacent the wicking material layer.
 5. An insulationproduct for exterior walls according to claim 4, wherein: the sorbentregion is formed by coating an outer region of the primary insulatinglayer with a sorbent material.
 6. An insulation product for exteriorwalls according to claim 4, wherein: the sorbent region is materiallayer provided between the primary insulating layer and the wickingmaterial layer.
 7. An insulation product for exterior walls according toclaim 1, wherein: the extending portion of the wicking material layer isarranged and configured to extend beyond a plane defined by the innersurface of the primary insulating layer and into an insulated space. 8.An exterior wall insulating system comprising: an insulating elementincluding a primary insulating layer having an inner surface, an outersurface and lower surface; and a wicking material layer having a primaryportion provided on the outer surface of the primary insulating layerfor collection and transport of a liquid and an extending portionpositioned below the lower surface for evaporation of the liquid; and asupporting element arranged and configured to support the insulatingelement and accommodate the extending portion of the wicking materiallayer.
 9. An exterior wall insulating system according to claim 8,further comprising: a sorbent material provided within the supportingelement and in contact with the extending portion of the wickingmaterial layer.
 10. An exterior wall insulating system according toclaim 8, further comprising: a sorbent material provided within thesupporting element and in contact with the extending portion of thewicking material layer.
 11. An exterior wall insulating system accordingto claim 8, further comprising: a heating element provided within thesupporting element and in proximity to the extending portion of thewicking material layer.
 12. An exterior wall insulating system accordingto claim 8, further comprising: a secondary evaporative materialprovided within the supporting element and in contact with the extendingportion of the wicking material layer.
 13. An exterior wall insulatingsystem according to claim 12, wherein: the secondary evaporativematerial is configured to increase an effective evaporative area.
 14. Anexterior wall insulating system according to claim 8, wherein: thesupporting element defines a passage through which a gas may be forcedalong the extending portion of the wicking material layer.
 15. Anexterior wall insulating system according to claim 8, wherein: thesupporting element includes a plurality of openings whereby vaporevaporating from the extending portion of the wicking material layer maypass into an insulated space.
 16. An exterior wall insulating systemaccording to claim 15, wherein: the supporting element includes trimelements that extend over a lower peripheral portion of the innersurface of the insulating element.
 17. An exterior wall insulatingsystem according to claim 15, wherein: the supporting element isarranged and configured to receive a trim element, the trim elementincluding regions that extend over a lower peripheral portion of theinner surface of the insulating element.
 18. An insulation product forexterior walls comprising: a primary insulating layer having an innersurface, an outer surface and lower surface; and a sorbent materiallayer having a primary portion provided on the outer surface of theprimary insulating layer for the collection, temporary retention andsubsequent evaporation of a liquid.
 19. A method for insulating exteriorwalls, the method comprising: fastening a primary support elementadjacent the exterior wall; installing an insulating element adjacentthe exterior wall, a lower surface of the insulating element beingsupported by the primary support element, the insulating elementincluding an extending portion of a wicking material layer that extendsthe primary support element; installing a trim element on the primarysupport element, the trim element including a portion covering a lowerperipheral surface of the insulating element.
 20. A method forinsulating exterior walls according to claim 19, further comprising:securing the extending portion of the wicking material layer withcooperating structures provided on the primary support element and thetrim element.